<template>

  <el-container class="home-container">
    <!--头部区域-->
    <el-header>
      <div>
        <img src="../assets/heima.png" alt="">
        <span>BGS后台管理系统</span>
      </div>
      <el-button type="info" @click="logout">退出</el-button>
    </el-header>
    <!--页面主题区域-->
    <el-container>
      <!--侧边栏-->
      <el-aside :width="isCollapse ?'64px':'200px'">
        <div class="toggle-button" @click="toggleCollapse">|||</div>
        <!--侧边栏菜单区-->
        <el-menu
          background-color="#333744"
          text-color="#fff"
          active-text-color="#409EFF"
          unique-opened
          :collapse="isCollapse"
          :collapse-transition="false"
          :router="true"
          :default-active="activePath">
          <!--一级菜单-->
          <el-submenu :index="item.id + ''" v-for="item in menulist" :key="item.id">
            <!--1级菜单模板区-->
            <template slot="title">
              <!--图标-->
              <i :class="iconsObj[item.id]"></i>
              <!--文本-->
              <span>{{item.authName}}</span>
            </template>
            <!--二级菜单-->
            <el-menu-item :index="'/'+subItem.path" v-for="subItem in item.children" :key="subItem.id"
                          @click="saveNavState('/'+subItem.path)">
              <template slot="title">
                <!--图标-->
                <i class="el-icon-menu"></i>
                <!--文本-->
                <span>{{subItem.authName}}</span>
              </template>
            </el-menu-item>
          </el-submenu>

        </el-menu>

      </el-aside>
      <!--右侧主体区域-->
      <el-main>
        <!--路由占位符-->
        <router-view>

        </router-view>
      </el-main>
    </el-container>
  </el-container>
</template>

<script>
export default {

  // 组件的私有数据
  data: function () {
    return {
      // 左侧菜单数据
      menulist: [],
      // 图标对象
      iconsObj: {
        125: 'iconfont icon-user',
        103: 'iconfont icon-tijikongjian',
        101: 'iconfont icon-shangpin',
        102: 'iconfont icon-danju',
        145: 'iconfont icon-baobiao'
      },
      // 是否者叠
      isCollapse: false,

      // 被激活地址
      activePath: ''

    }
  },

  created () {
    this.getMenuList()
    this.activePath = window.sessionStorage.getItem('activePath')
  },

  methods: {
    logout () {
      // 清空sessionSortage
      window.sessionStorage.clear()
      // 清空之后重定向回登录界面
      this.$router.push('/login')
    },

    // 获取所有的菜单
    async getMenuList () {
      const { data: res } = await this.$http.get('menus')
      // 状态码不等于200,获取失败，返回错误信息
      if (res.meta.status !== 200) return this.$message.error(res.meta.msg)
      this.menulist = res.data
      // console.log(res)
    },

    // 点击按钮,切换菜单的折叠与展开
    toggleCollapse () {
      this.isCollapse = !this.isCollapse
    },

    // 保存链接的激活状态
    saveNavState (activePath) {
      /*
          setItem()方法设置指定的存储对象项的值。setItem()方法属于Storage对象,可以是localStorage对象,
          也可以是sessionStorrage对象。
          */
      window.sessionStorage.setItem('activePath', activePath)
      this.activePath = activePath
    }
  }
}
</script>

<style lang="less" scoped>

  .home-container {
    height: 100%;
  }

  .el-header {
    background-color: #373d41;
    display: flex;
    /*把子元素靠边对齐平均分剩余的空间-->两个元素就是左右对齐*/
    justify-content: space-between;
    padding-left: 0;
    /*居中对齐*/
    align-items: center;
    /*字体颜色*/
    color: #ffffff;
    font-size: 20px;

    > div {
      display: flex;
      align-items: center;

      span {
        margin-left: 15px;
      }
    }
  }

  .el-aside {
    background-color: #333744;

    .el-menu {
      border-right: none;
    }
  }

  .el-main {
    background-color: #EAEDF1;
  }

  .iconfont {
    margin-right: 10px;
  }

  .toggle-button {
    background-color: #4A5064;
    font-size: 10px;
    color: #ffffff;
    line-height: 24px;
    text-align: center;
    /*letter-spacing 属性增加或减少字符间的空白（字符间距）*/
    letter-spacing: 0.3em;
    cursor: pointer;
  }

</style>
